diff --git a/bin/package.js b/bin/package.js
index d92eedce..c89104bc 100755
--- a/bin/package.js
+++ b/bin/package.js
@@ -1,7 +1,7 @@
 #!/usr/bin/env node
 
 /**
- * Builds app binaries for Mac, Linux, and Windows.
+ * Builds app binaries for Mac, Windows, and Linux.
  */
 
 var cp = require('child_process')
@@ -493,6 +493,9 @@ function buildWin32 (cb) {
       var downloadsPath = path.join(portablePath, 'Downloads')
       mkdirp.sync(downloadsPath)
 
+      var tempPath = path.join(portablePath, 'Temp')
+      mkdirp.sync(tempPath)
+
       var archStr = destArch === 'ia32' ? '-ia32' : ''
 
       var inPath = path.join(DIST_PATH, path.basename(filesPath))
diff --git a/src/config.js b/src/config.js
index 01764fb3..3712719d 100644
--- a/src/config.js
+++ b/src/config.js
@@ -116,9 +116,7 @@ function getConfigPath () {
 }
 
 function getDefaultDownloadPath () {
-  if (!process || !process.type) {
-    return ''
-  } else if (IS_PORTABLE) {
+  if (IS_PORTABLE) {
     return path.join(getConfigPath(), 'Downloads')
   } else {
     return getPath('downloads')
@@ -126,9 +124,14 @@ function getDefaultDownloadPath () {
 }
 
 function getPath (key) {
-  if (process.type === 'renderer') {
+  if (!process.versions.electron) {
+    // Node.js process
+    return ''
+  } else if (process.type === 'renderer') {
+    // Electron renderer process
     return electron.remote.app.getPath(key)
   } else {
+    // Electron main process
     return electron.app.getPath(key)
   }
 }
@@ -159,6 +162,7 @@ function isPortable () {
 
 function isProduction () {
   if (!process.versions.electron) {
+    // Node.js process
     return false
   }
   if (process.platform === 'darwin') {
diff --git a/src/main/index.js b/src/main/index.js
index cae3398f..17c30b71 100644
--- a/src/main/index.js
+++ b/src/main/index.js
@@ -33,9 +33,11 @@ if (process.platform === 'win32') {
   argv = argv.filter((arg) => !arg.includes('--squirrel'))
 }
 
-if (!shouldQuit) {
+if (!shouldQuit && !config.IS_PORTABLE) {
   // Prevent multiple instances of app from running at same time. New instances
-  // signal this instance and quit.
+  // signal this instance and quit. Note: This feature creates a lock file in
+  // %APPDATA%\Roaming\WebTorrent so we do not do it for the Portable App since
+  // we want to be "silent" as well as "portable".
   shouldQuit = app.makeSingleInstance(onAppOpen)
   if (shouldQuit) {
     app.quit()
@@ -48,7 +50,11 @@ if (!shouldQuit) {
 
 function init () {
   if (config.IS_PORTABLE) {
+    const path = require('path')
+    // Put all user data into the "Portable Settings" folder
     app.setPath('userData', config.CONFIG_PATH)
+    // Put Electron crash files, etc. into the "Portable Settings\Temp" folder
+    app.setPath('temp', path.join(config.CONFIG_PATH, 'Temp'))
   }
 
   const ipcMain = electron.ipcMain